title: The diagnostic value of the anti-PF4/heparin immunoassay high-dose heparin confirmatory test in cardiac surgery patients.
abstract: There are limited and conflicting data on how a confirmatory step using high-dose heparin can improve diagnostic specificity of the antiplatelet factor 4/heparin enzyme immunoassay for heparin-induced thrombocytopenia (HIT). We investigated sera from a recently published study on cardiac surgery patients and found that only half of the sera that were heparin-induced platelet activation assay positive could be inhibited (optical density <40%) by high-dose heparin (100 IU/mL) in the enzyme immunoassay. More importantly, only 2 of the 3 patients with definite HIT were confirmatory test positive. Therefore, the high-dose heparin confirmatory test should be used with caution to exclude platelet-activating antiplatelet factor 4/heparin antibodies or clinical HIT.
authors.affiliation: Klinik und Poliklinik für Anästhesiologie und Intensivmedizin, Ernst-Moritz-Arndt-Universität Greifswald, Friedrich-Loeffler-Strasse 23b, 17475 Greifswald, Germany. sselleng@uni-greifswald.de
authors.forename: Sixten
authors.initials: S
authors.lastname: Selleng
authors.forename: Natalie
authors.initials: N
authors.lastname: Schreier
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Wollert
authors.forename: Andreas
authors.initials: A
authors.lastname: Greinacher
mesh_terms: D006348:Cardiac Surgical Procedures / Q000009:adverse effects; D006493:Heparin / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007518:Isoantibodies / Q000096:biosynthesis / Q000502:physiology; D015539:Platelet Activation / Q000276:immunology; D010978:Platelet Factor 4 / Q000276:immunology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013921:Thrombocytopenia / Q000097:blood / Q000139:chemically induced / Q000175:diagnosis
chemical_list: D007518:Isoantibodies; D010978:Platelet Factor 4; D006493:Heparin